Transistor switching devices in a gas tube coincidence matrix selector



Feb. 26, 1963 P. BU RSTOW ETAL TRANSISTOR SWITCHING DEVICES IN A GAS TUBCOINCIDENCE MATRIX SELECTOR Filed Oct. 21, 1958 +V a (V INVENTORS PIERREBURSTO w CLAUDE MON/N ilnited states Patent 1 3,679,588 TRANSISTQRSWITCHENG DEVECES IN A GAS TUBE CDINCIDENQE MATRIX SELECTOR PierreBurstow, Paris, and Claude Monin, Villennes-sur- Seine, Seine ct Oise,France, assignors to Comnagnie l'ndustriellc des Telephones, Paris,France, a French corporation Filed (Pct. 21, 1958, Ser. No. 768,640Claims priority. application France Nov. 8, 1957 7 Claims. (Cl. 340-166)The present invention relates to a controlling device which can be usedespecially in electronic switching and which permits of controlling bystatic means the transmission of an alternating current from one pointto another.

Devices of this type are already known, for example from French Patent1,126,635, filed on May 21, 19-55, and the French Patent 1,160,892,filed by applicants on November 23, 1956. However, in these devices, thealternating current, in passing from a point .A to a point B, must flowthrough two electrochemical condensers of relatively high capacitancewhich do not, in some cases, have suificient robustness, especially inthe case of equipment which has to undergo shocks.

The device according to the invention is characterised by the fact thatit comprises a transistor disposed between the two points to beconnected, the transistor being rendered conductive or non-conductivefor alternating current as required, in accordance with the potentialconnected to its base, which latter may be connected, in the case of apnptype transistor, either to a positive polarity of higher absolutevalue than the emitter, or to a negative polarity in relation to theemitter. In order that the point connected to the base of the transistormay thus change polarity as required, it is connected on the one hand toa positive polarity through a resistance and on the other hand to theanode of a gas tube having an auxiliary anode.

When the gas tube is fired, a current passes therethrough which producesa voltage drop across the resistance and varies the potential of thebase to a sufficient extent to render the transistor conductive. The gastube may lire under two conditions corresponding to two controlsapplied, one to the cathode and the other to the auxiliary anode.

The device according to the invention is particularly interesting whenemployed in a selecting matrix comprising circuits disposed inhorizontal lines and circuits disposed in vertical lines crossing thesaid horizontal lines and for effecting the connection between anyhorizontal line and any vertical line by means of a connecting pointdevice disposed at each crossing of a horizontal line and of a verticalline, the emitter and the collector or" the transistor each beingconnected to a separate line and the anode of each gas tube being fedthrough a separate resistance from a voltage source common to the anodesof a single line, the auxiliary anode of each tube being fed throughanother separate resistance and the separate resistances of theauxiliary anodes of the tubes of one horizontal line being connected toa common point which is in turn connected to a switch for theapplication of voltage, the cathodes of the tubes of one vertical linebeing connected to a common point which in turn is connected to a commonresistance in series with a switch for the application of voltage, theconnection between one horizontal line and one vertical line beingefiected by closing of a switch of the horizontal line and by a switchof the vertical line, which latter two operations result in the firingof the tube situated at the crossing point of the two lines, while theoperation of the tube is maintained as long as the cathode switch re-"ace mains closed, and no other tube of the same vertical line beingable to become operative as long as the tube in operation itself remainsoperative.

Further features and advantages of the invention will become apparentfrom the description thereof which is herinafter given with reference tothe accompanying drawings, which show by Way of example constructionalforms of the device according to the invention.

FIGURE 1 illustrates diagrammaticallly a simple link according to theinvention between a point A and a point B.

FIGURE 2 illustrates a modification of FIGURE 1.

FIGURE 3 illustrates a matrix comprising m lines and q columns adaptedto establish mq links.

In FIGURE 1, there are shown two points A and B between which it isdesired to permit or interrupt the flow of an alternating current whenrequired, without using movable contacts. The point A may be connectedto earth by a switch K and is connected at C to the emitter of atransistor T. The point B is connected at D to the collector of the sametransistor and the base of the said transistor is connected to a point Bthrough a resistance Rb. The point E is connected on the one hand to thepositive pole of a direct voltage source +V through a resistance W andon the other hand to the anode of a gas triode L. The cathode of thetriode L is connected to the negative pole -V of a direct 'voltagesource through a resistance R and a switch V. The auxiliary electrode ofthe triode is connected to the positive pole +Vs of a direct voltagesource through a resistance r and a switch H. It is therefore necessary,for firing the tube L, to apply voltage simultaneously to the auxiliaryelectrode and to the cathode, that is to say, to close the switches Hand V. The device operates as follows: in the case of a junctiontransistor of the pup-type it is necessary for its emitter to beposittive in relation to the base in order that it may be debIOcked.When the triode is not fired, the base is conneoted to a positivepotential in relation to the emitter. Since the latter is earthed, thetransistor is blocked. If the triode is fired by closing of the switchesH and V and if the switch H is thereafter opened, the triode continuesto operate and a current flows therethrough between the anode and thecathode. The voltage drop due to this current across the resistance W issuflicient for the potential of the point B to fall below that of thepoint A if the values of the polarities and of the resistances areappropriately chosen. At this instant, since the transistor isdeblocked, it provides for collecting at its collector substantially thesame alternating-current which has been applied to the emitter. In orderto block the transistor again, it is sufiicient to interrupt the currentflowing through the triode by opening the switch V, the point B thenreturning to a positive potential in relation to the emitter.

FIGURE 2 is a modification of FIGURE 1 and does not dififer therefrom inits principle, but solely in the manner in which the gas triode isstruck. The base of the transistor is always connected to the point Ethrough the resistance Rb and the point E is always connected on the onehand to the positive potential +V through the resistance W and on theother hand to the anode of the valve L. However, the cathode is hereconnected, without the interposition of a switch, on the one hand to thenegative potential -V through the resistance R and on the other hand tothe electrode of a condenser P whose other electrode is earthed. Theauxiliary electrode of the triode L is connected to a point G comprisingtwo symmetrical links, each of these links being formed by theconnection of the point G to a positive polarity +Vs through aresistance d and a switch H. Connected to the point I, situated afterthe resistance d and bet re the switch H, is a resistance e, the otherend of which is at the negative potential Vs. The operation is asfollows:

.the gas triode is fired merely by action on the auxiliary electrode,since the anode and the cathode comprise no switches and are connectedto fixed polarities +V and -V respectively. if a single switch H isclosed and the value of the resistance e is made small in relation to(I, the point G reaches a potential substantially equal to 7 .stop'theoperation, the switch Kc is operated and applies to the condenser P thevoltage u existing between the point P and earth. The condenser P ischarged with a quantity of electricity Q=P.u (P representing thecapacitance of the condenser). This quantity of electricity may besuilicient to produce the immediate extinction of the gas tube (if P issuificiently high).

FIGURE 3 illustrates a matrix comprising in horizontal rows and qvertical columns, only the rows X X and X and the columns Y Y and Yhaving been drawn. Any rows such as X can be connected to any columnsuch as Y; by the operation of a transistor T situated at their crossingpoint if therappropriate voltages for producing the firing of a gastriode L have been applied as seen with reference to FIGURE 1. Eachcrossing point (or each connecting point) is thus formed in accordancewith FIGURE 1, in which the arrow fH corresponds to the multiplying ofthe emitters on a common horizontal row, the arrow v corresponds to themultiplying of the collectors on a common vertical column, the arrow atthe point P of the cathode corresponds to the multiplying of. a commonresistance such as R c for feeding the cathodes ofa common column by thepotential -V and finally the arrow V corresponds to the multiplying ofthe anode voltage V at the separate resistances W 1, W l t W thismultiplying being effected by columns (or by rows). The voltage Vs isdistributed by horizontal rows by means of the switches H H H Theoperation is as follows: it will be assumed that it is necessary toestablish a call between the row X and the column Y the wire X havingpreviously been earthed. It is therefore necessary to render conductivethe transistor T situated at the crossing point. The anode voltage Vhaving been applied to the various separate resistances W W W of thefirst column, voltage is applied to the tube L In order that the tubemay be struck, two other conditions must be satisfied, one beingreprezsentedby a horizontal control and the other by a vertical:control. The horizontal control consists in closing the switch H forapplying the potential Vs to the auxiliary anode of the tube L throughthe resistance r It will be seen that this potential Vs is at the sametime applied to all the auxiliary anodes of the second row. The verticalcontrol consists in closing the switch V for feeding the variouscathodes of the same column through the common resistance R C. Amongthese cathodes, the cathode of the tube L is fed. Gnly the tube L hasits anode, its auxiliary anode and its cathode fed, and it fires. Thepoint E has its potential varied and the transistor T becomesconductive. The alternating current can then flow from X to Y Thefeeding of the tube L produces a voltage drop across the resistance R C,and if a voltage Vs is applied to the auxiliary anode of another tube ofthe same column during the operation, this tube will then be incapableof firing, since the potential applied to the cathode of this other tubeis notVn, but V minus the voltage drop across the common resistance R C.An automatic blocking therefore occurs and protects a tube in operationin a column. in other words, only one tube can operate at a time in onecolumn. -t is also to be noted that if the voltage Vs is suppressed atthe auxiliary anode, the tube L memorises its operation and continues tooperate between the anode and the cathode. In order t stop theoperation, it is necessary to open the switch V providing the cathodepotential.

The circuit arrangement illustrated in FIGURE 3 is an application to amatrix of the arrangement illustrated in FEGURE 1. It would similarlyhave been possible to illustrate a matrix arrangement whose basiccircuit is that of FIGURE 2 Modifications of the device according to theinvention can readily be made by the use of transistors on npn-type,

with which it is sufiicient to vary the polarities accordin ly. Thesemodifications obviously fall within the scope of this invention. a

We claim:

l. A transistor switching device in a gas tube coincidence matrixselector, comprising a transistor interconnecting two lines of a matrix,said transistor having acontrol electrode for selectively blocking andunbloclcing said transistor depending on the potential of said controlelectrode, a resistance connected at one end to said control electrode,a multielcctrode gas tube including at least an anode, a cathode and anauxiliary anode, and having said anode connected to the other end orsaid resistance, means including a second resistance connected to saidanode of said gas tube for applying a control voltage to block saidtransistor and simultaneously acting as supply voltage for said anode ofthe gas tube, and means for firing said gas tube to change the potentialof said control electrode and thereby unblock said transistor, saidlastmentioned means comprising two switches and means operative-1yconnecting said switches to jointly control the firing of said gas tube.

2. A switching device according to claim 1 including means forconnecting the auniliary'anode of the gas tube to a direct currentsource through a resistance and one of said switches and means forconnecting the cathode of the gas tubeto another direct current sourcethrough resistance and the other of said switches, the firing of saidtube being eilected by closing the two switches.

3. A switching device according to claim 1, wherein said means forfiring said gas tube includes two identical circuits connected to theauxiliary anode of the gas tube, each of said identical circuitsincluding a resistance connected by one of said switches to a directcurrent source and including a further resistance connected from a pointintermediate the aforementioned resistance and switch of- 7 said circuitto the opposite pole of said last-mentioned direct current source, saidtube being capable of firing only if the switches of each of said twoidentical circuits are closed.

4. A switching device according to claim 3 including means forconnecting the cathode of the gas tube on the one hand through aresistance to a direct'current source and on the other hand through acondenser and a further switch means adapted to be connected to ground,the closing of said last-mentioned switch means during operation of thegas tube producing extinction of the tube.

5. A switching device according to claim 1, wherein said transistorincludes emitter collector electrodes connected to said lines,respectively.

6. A selecting matrix employing a plurality of switching devicesaccording to claim 5, comprising circuits disposed in horizontal linesand circuits disposed in vertical lines crossing the horizontallines'and providing'for establishment of a connection between anyhorizontal line and vertical line, onesuch switching device beingdisposed at each crossing point of the horizontal line and of a verticalline, the emitter and collector of the transistor of each said deviceeach being connected to a separate line of the respective crossed lines,means for energizing the anode of each gas tube through said secondresistance by a voltage source common to the anodes of the tubes of eachvertical line, means for energizing the auxiliary anode of each tubethrough at least one other resistance, the last-mentioned resistances ofthe auxiliary anodes of the tubes of a common horizontal line beingconnected to a common point which is in turn connected by control switchmeans for the application of a control voltage, each vertical linecomprising means including a control circuit for applying a secondvoltage to the cathode of each of the gas tubes of the respectivevertical line, the connection between a horizontal line and a verticalline being established by the operation of both the respective firstmentioned control switch means of the horizontal line and the respectivesecond-mentioned control circuit of the vertical line, these twooperations producing the firing of the tube situated at the crossingpoint of the two lines and the operation of the tube being maintained aslong as the respective gas tube remains conductive, while no other tubeof the same vertical line can come into operation as long as the tube inoperation itself remains operative.

7. A selecting matrix employing a plurality of switching devicesaccording to claim 5, comprising circuits disposed in horizontal linesand circuits disposed in vertical lines crossing the horizontal line andproviding for establishment of a connection between any horizontal lineand any vertical line, one such switching device being disposed at eachcrossing point of a horizontal line and of a vertical line, the emitterand the collector of the transistor of each said device each beingconnected to a separate line of the respective crossed lines, means forenergizing the anode of each gas tube through said second resistancefrom a voltage source common to the anodes of the tubes of each verticalline, means for energizing the auxiliary anode of each tube throughanother resistance, said lastmentioned resistances of the auxiliaryanodes of the tubes of each common horizontal line being connected to acommon point which is in turn connected to a control switch for theapplication of a control voltage, each said last-mentioned controlswitch constituting one of the two switches of each device along therespective horizontal line, each vertical line comprising a resistanceand a control switch in series therewith connected to each of thecathodes of the gas tubes of the respective vertical line for applyingthereto a control voltage, each said last-mentioned control switchconstituting the other of the two switches of each device along saidrespective vertical line, the connection between a horizontal line and avertical line being established by the closing of both the respectivefirst-mentioned control switch of the horizontal line and the respectivesecond-mentioned control switch of the vertical line, these twooperations producing the firing of the tube situated at the crossingpoint of the two lines and the operation of the tube being maintained aslong as the last-mentioned switch remains closed, while no other tube ofthe same vertical line can come into operation as long as the tube inoperation itself remains operative.

References Qited in the file of this patent UNITED STATES PATENTS2,603,716 Law July 15, 1952 2,627,039 MacWilliams Ian. 27, 19532,809,394 Dickinson Oct. 8, 1957 2,853,629 Felker Sept. 23, 19582,914,747 Straube Nov. 24, 1959 2,954,508 Burstow Sept. 27, 19603,015,697 Klinkhamer Ian. 2, 1962

1. A TRANSISTOR SWITCHING DEVICE IN A GAS TUBE COINCIDENCE MATRIXSELECTOR, COMPRISING A TRANSISTOR INTERCONNECTING TWO LINES OF A MATRIX,SAID TRANSISTOR HAVING A CONTROL ELECTRODE FOR SELECTIVELY BLOCKING ANDUNBLOCKING SAID TRANSISTOR DEPENDING ON THE POTENTIAL OF SAID CONTROLELECTRODE, A RESISTANCE CONNECTED AT ONE END TO SAID CONTROL ELECTRODE,A MULTI-ELECTRODE GAS TUBE INCLUDING AT LEAST AN ANODE, A CATHODE AND ANAUXILIARY ANODE, AND HAVING SAID ANODE CONNECTED TO THE OTHER END OFSAID RESISTANCE, MEANS INCLUDING A SECOND RESISTANCE CONNECTED TO SAIDANODE OF SAID GAS TUBE FOR APPLYING A CONTROL VOLTAGE TO BLOCK SAIDTRANSISTOR AND SIMULTANEOUSLY ACTING AS SUPPLY VOLTAGE FOR SAID ANODE OFTHE GAS TUBE, AND MEANS FOR FIRING SAID GAS TUBE TO CHANGE THE POTENTIALOF SAID CONTROL ELECTRODE AND THEREBY UNBLOCK SAID TRANSISTOR, SAIDLASTMENTIONED MEANS COMPRISING TWO SWITCHES AND MEANS OPERATIVELYCONNECTING SAID SWITCHES TO JOINTLY CONTROL THE FIRING OF SAID GAS TUBE.